Interestingly, I was able to start the 4.4 vkernel some time ago, but I recently recompiled it and it started to crash the same way 4.6 does. I still have access to my working 4.4 vkernel, but don't know what to compare to see the difference.

- During ap_init() any pending IPIs is processed manually so
clear gd_npoll as the real kernel does.
- Do not disable interrupts for vkernels during lwkt_send_ipiq3()
because they don't seem to be re-enabled afterwards as they should.
I'm not entirely sure this is the right fix, more investigation
is required.

I'm closing this ticket because the problem was solved for me. But I wander if it makes sense to back-port (basically cherrypick and submit as there are no conflicts) the two commits that solved the problem from master to DragonFly_RELEASE_4_6?